Senergy advises electricity generators to check their bills

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Leading global energy services company Senergy is advising electricity generators connected to the distribution network to double check their bills to ensure their charges have been calculated according to the correct industry methods.

Senergy’s advice comes after a review for one of its clients, a wind farm developer, found that they had been mischarged by around £400 per month for Distribution Use of System (DUoS) charges. DUoS is paid to the Distribution Network Operator (DNO) to whose network a user is connected.

Senergy’s client believed that they were being charged DUoS charges for a significantly higher electricity demand than their wind farm site used and asked Senergy to investigate.

Senergy’s review verified that the client had been mischarged due to an incorrect value of chargeable import capacity being used in DUoS charge calculations.

Dr Jason Hill, power engineering manager for UK & Northern Europe at Senergy, said: “A generation site will import and export both active (kW) and reactive (kVAr) power.  Import of active power is used to supply on-site loads such as ancillary equipment when not generating electricity.  “A generator may import reactive power and, at the same time, export active power.  However, any chargeable import capacity calculated under these circumstances does not accurately reflect the demand of a site because no active power is imported.”

As part of its review, Senergy liaised with the local DNO, whose method of calculating import capacity for the site involved using reactive power import during periods of active power export.  However, when Senergy highlighted that the method used did not meet Ofgem-approved methodology, the DNO provided a full rebate of the additional costs charged.Dr Hill said: “The client received a significant rebate because they were estimated to have been overcharged by around £400 per month, dating back 10 months.  However, the main value to the client is the change to all future DUoS charges, as mischarging could have continued if left unchecked.”

Dr Hill believes a large number of generators could also be being mischarged without realising it: “Due to the fact that a number of factors have to be taken into consideration when calculating DUoS charges, it can be quite complex and many users may not be sure how to work out if they’ve been correctly charged.

“We would advise users to double check their bills and, if they are unsure if they have been charged correctly, then to seek professional advice.”

Most generators connected to the distribution network pay GDUoS charges to the DNO for energy exported onto the network and DUoS charges for energy imported from the network.  Both GDUoS and DUoS charges are passed on to the generator by their electricity supplier.

Senergy advises generators on their likely DUoS / GDUoS liabilities, particularly at the early phase of development when it makes sense to consider the liabilities, which vary against different connection options.  Each DNO has its own DUoS / GDUoS charging methodology and statement of charges although they now follow a common format.

Senergy’s integrated renewables capabilities also include a Survey and GeoEngineering division. With offices in Aberdeen, Bath, Newcastle and London, the division’s services include project management, geophysics, geotechnical engineering, survey and positioning, and data management.